<!DOCTYPE html>
<html>
<head>
	<title></title>
</head>
<body>
	<span id="h"></span>:
	<span id="m"></span>:
	<span id="s"></span>
</body>
<script>
	var num=5000;

	

	var h = document.getElementById("h");

	var m = document.getElementById("m");

	var s = document.getElementById("s");

	function sub()
	{
		num--;

		var st = num%60;

		var ht = parseInt(num/60/60);

		var mt = parseInt(num/60%60);

		if(ht<10)
		{
			h.innerHTML = '0'+ht;
		}
		else
		{
			h.innerHTML = ht;
		}

		if(st<10)
		{
			s.innerHTML = '0'+st;
		}
		else
		{
			s.innerHTML = st;
		}

		if(mt<10)
		{
			m.innerHTML = '0'+mt;
		}
		else
		{
			m.innerHTML = mt;
		}

		if(num<=0)
		{
			clearInterval(timer);
		}
	}

	var timer = setInterval(sub,10);

	

</script>
</html>